Changes will need to be implemented before they can take off.

Recently, Boeing announced that they were close to receiving approval to begin using their grounded fleet of 737 Max jets for passenger flights once again. After a long period of grounding following two devastating plane crashes, the 737 Max fleet will be taking to the skies once again, pending some additional tweaks.

The Federal Aviation Administration announced today that Administrator Steve Dickson had signed the formal order to allow the 737 Maxes to carry passengers again. This green light follows a lengthy, 20-month inspection process that verified every last aspect of the jets and pinpointed any potential problems. The FAA’s approval was corroborated by the Air Line Pilots Association, who said in a statement of their own that they believe “the engineering fixes to the flight-critical aircraft systems are sound and will be an effective component that leads to the safe return to service of the 737 MAX.”

With Dickson’s order, Boeing will be able to deploy the 737 Maxes again, though first some new changes must be implemented. In a 115-page “Airworthiness” directive, the FAA outlined some vital changes that must be made to the jets’ construction, both on the existing grounded fleet and any new 737 Maxes that are constructed. Additionally, the FAA has published new training and conduct guidelines specifically for pilots of the 737 Max, as well as maintenance requirements for any airports that house them. Once these new requirements have been met to the FAA’s satisfaction, Boeing will be free to use the jets again.

The FAA has stressed that even once the 737 Maxes enter into use again, they will be keeping a close eye on the jets and Boeing’s usage of them, with additional aid from foreign aviation partners around the world.